.ılı.ılı. CiscoBlog Brasil .ılı.ılı.

A algum tempo atrás escrevi um post falando um pouco sobre o XR4U,  o equivalente ao IOU para IOS-XR.

O XR4U emula o software IOS-XR em servidores, geralmente máquinas virtuais rodando UNIX/Linux. Apesar de suas limitações, é possível testar um número considerável de funcionalidades.

O laboratório disponível atualmente no PEC conta com 5 diferentes exercícios:

Lab Exercise 1: IOS XR Introduction
Lab Exercise 2: IOS XR Routing
Lab Exercise 3: IOS RPL
Lab Exercise 4: IOS XP MPLS
Lab Exercise 5: IOS XR Multicast

Quem tiver interesse, basta acessar o PEC (somente para Cisco Partners) e procurar por “GOLDLab: IOS-XR Instruction”.

Abraços.

Diogo.

Leia também:

• Emulador para IOS-XR
• Novo CCNP® Service Provider Certification
• Cisco aumenta o custo para se tornar um profissional CCIE
• Mobile CCIE Lab agora também para CCIE Voice
• Cisco Live! 365

Olá,

Multicast é um assunto que costuma deixar alguns profissionais com muitas dúvidas. Acredito que isso aconteça não tanto pela complexidade (o conceito básico é bem simples), mas sim pela falta de prática. Isso acontece também no que se refere a IPv6. Não é um “bicho de sete cabeças” , apenas não é visto com tanta frequência, principalmente em ambientes “Enterprise”.

Pensando nisso, achei interessante divulgar uma série de vídeos (disponíveis para visualização no YouTube) que explicam os conceitos básicos sobre o assunto:

Multicast 1 – Intro
http://www.youtube.com/watch?v=AvbSMBKBZgY

Multicast 2 – Addressing
http://www.youtube.com/watch?v=1_4MOkjfX7I

Multicast 3 – Components
http://www.youtube.com/watch?v=sM0oQxYfbys

Multicast 4 – PIM Dense Mode
http://www.youtube.com/watch?v=zBiEztnKfyw

Multicast 5 – PIM Sparse Mode
http://www.youtube.com/watch?v=OMRByA64xuA

Multicast 6 – Auto RP
http://www.youtube.com/watch?v=KpZTf4KC3tE

Eu particularmente gosto muito de vídeo aulas como método inicial de estudos, passando posteriormente para a leitura de livros e documentações. Considero a explicação do Anthony bem didática e simples, o que facilita o entendimento principalmente para quem não tem facilidade com o inglês.

Espero que estes vídeos possam ajudar aos colegas que estão estudando o assunto para exames de certificação ou mesmo em seu dia a dia de trabalho.

Abraços.

Diogo.

Leia também:

• Cisco pretende lançar oficialmente o software IOU
• Treinamento Juniper: Day One

Olá!

Depois de um bom tempo fora por motivos técnicos e pessoais, o blog está de volta

Estou sem muito tempo para me dedicar ao projeto (atualmente mais do que nunca), mas tentarei mantê-lo vivo e atualizado tanto quanto possível.

E para começar essa nova fase, achei interessante divulgar uma fonte de informação que acredito ser muito pouco explorada aqui no Brasil. Trata-se do Cisco Live! 365.

Este site disponibiliza material derivado dos eventos Cisco Live! que acontecem normalmente duas ou três vezes por ano em diversos países, e reúne profissionais do mundo inteiro.

A diversidade de assuntos é impressionante e a qualidade do conteúdo também! Existe muita coisa nova de mercado ainda pouco documentada, temas que abordam novidades e assuntos específicos que podem vir a ser extremamente úteis em nosso dia a dia, seja em novos projetos, suporte, operação, ou mesmo com foco em certificações.

Bom, não é? Bem, pra melhorar, tudo isso ainda é disponibilizado sem custo! Isso mesmo, é FREE

https://www.ciscolive365.com/connect/createAccount.ww

Basta efetuar o cadastro e você terá acesso a tudo isso.

Abraços.

Diogo.

Leia também:

• Cisco pretende lançar oficialmente o software IOU
• Cisco aumenta o valor do exame CCNA/CCDA!
• Cisco aumenta o custo para se tornar um profissional CCIE
• Mobile CCIE Lab agora também para CCIE Voice
• XR4U disponível no PEC

Dica dos colegas minicz e pablod (http://blog.ccna.com.br/forum/comments.php?DiscussionID=6505):

DHCP

• DHCP jokes are leased.
• A DHCP packet walks into a bar and asks for a beer. Bartender says: “here, but I’ll need that back in an hour!

DNS

• The best thing about DNSSEC jokes is that you can check if they were told wrong.

Ethernet

• I had an Ethernet joke, but somebody else told it at the same time. So I exponentially backed off and tried again.
• {1,Two guys}{2,Hear about}{1,are talking}{2,the dope}{1,in}{2,who confused}{1.full-duplex,}{2,TDM with full-duplex?}
• LAN jokes can only be told properly if you tell an STP joke first.
• You have to tell a broadcast joke to everybody to find the one who see the fun on it.
• Broadcast your own ARP jokes, mine are only funny within the same collision domain.
• ARP jokes are often gratuitous.
• An ARP request goes to McDonald’s and asks for a Big MAC.
• I like ARP jokes, because it’s so easy to make them appear to originate from other persons.

IPv4

• An IPv4 address walks into a bar and says: “Quick, give me a drink. I am exhausted!”
• The worst thing about protocol jokes is the ridiculous TTL.
• I’d tell you the one about the CIDR block, but you’re too classy.
• Didn’t we run out of IPv4 jokes?
• After dropping the packet the IP said it was my best effort.
• RFC1918 jokes are inside jokes.
• IP packet with TTL=1 arrives at bar. Bartender: “Sorry, can’t let you leave… and you don’t get any beer either…”
• Router: It hurts when IP.
• Network pray: Dear Lord, Please grant me the ability to punch people in the face over standard TCP/IP.
• We need to find more space for the IPv4 Comedy Roadshow, since all seats are taken.
• There’s no place like 127.0.0.1.
• I have told IPv4 joke 254 times. Then it stopped being funny.
• I have told IPv4 joke to my friend. He checked checksum and had best effort laugh.
• I have tried to tell you IPv4 joke, but you were unreachable.

IPv6

• The bad thing about IPv6 jokes is that nobody wants to tell them first.
• The best part about IPv6 jokes is that you don’t have to make up the punchline for 15 years.
• The great thing about Teredo jokes is that you can tell smart jokes even when surrounded by dumb peers.
• The problem with IPv6 jokes is they’re long, obscure and no one gets them without a translation.
• I know a great IPv6 joke, but I just don’t think you’re ready for it.
• An IPv6 packet walks into a bar. Nobody talks to him.
• The great thing about Teredo jokes is that you can tell smart jokes even when surrounded by dumb peers.
• I will tell you IPv6 joke, but first I need to tell you IPv4 joke, so you get it.

Multicast

• Sometimes I feel like a multicast packet. Ask 10 different people how to get somewhere and get 10 different answers.
• A multicast packet walks into a bar and leaves by four different exits at the same time.
• A multicast packet walks into 100 bars at one time.

Routing

• Is “smoke signal” a routable protocol?
• I’d like to tell you the full joke about a BGP table but I don’t think you can remember it all.
• The best thing about RIP jokes is that they’re funny 15 more times.
• The strange thing about BGP jokes is that they’re borderline funny but everybody repeats them anyway.
• A LSA Type 6 packet walks into a bar and asks the bartender for a drink. The bartender ignores him.
• A LSA Type 2 packet walks into a bar and asks for a beer. Bartender say’s “here, but don’t leave the area with it.”
• Q. What did the OSPF router say to the other OSPF router ? A. Hello. Hello. Hello. Hello. Hello. Hello. Hello. Hello.
• Five routers walk into a bar. Who gets the car keys? The Designated Router.
• Is IS-IS = 0 ?
• People who tell routing jokes always exceed their time-to-live.
• My new OSPF neighbor told me all his jokes after we said hello to each other. Then he tells me the whole database of jokes every 30 minutes.
• I keep telling him all my RIP jokes, but he is passive about it.
• I was asking all my neighbors for an EIGRP joke. Didn’t receive all replies, so I am stuck in active.
• Son, If I fail to route jokes to this destination, I want you to be my feasible successor. You have good distance.
• I told EIGRP all my OSPF jokes. EIGRP said that they are infinite.
• I would tell a BGP joke, but everyone probably already knows it.
• The great thing about BGP jokes? Anyone can claim they are their own, all you can do is hope your neighbours like them.
• I just heard 300.000 BGP jokes.
• I was arguing with my neighbor about who will tell great new BGP joke. I was locally more preferred joke teller, but didn’t want to compete with his weight.

Security

• SSH 1.33 and/or 1.5 protocol jokes are useless.
• I heard a great one about IPSEC, but you wouldn’t get it — it’s an inside joke.
• There are no good DH jokes because nobody agrees on the same prime.
• The problem with a cryptography joke is that you need to tell a pair of them before anyone understand what’s being said.
• Why are ASAs so noisy? They don’t know how to ssh.
• He said he was open to networking, but when we met up, he didn’t make a PEAP.
• The great thing about HTTP Upgrade jokes is… wait, someone might be listening, come closer add I’ll whisper.
• The great thing about TLS jokes is that you can tell if it’s not original.

TCP & UDP

• The problem with UDP jokes: I don’t get half of them.
• In high society, TCP is more welcome than UDP. At least it knows a proper handshake.
• arrival order packet joke is critical to good a make
• T he bes thin gabou tTCPfl owcontr oljokesi sthatthey knowwhento backo ff….
• I was promised a three way and all I got was a TCP handshake.
• A TCP packet walks in to a bar and says “I want a beer”, barman says “you want a beer?” and TCP packet says “yes, a beer”.
• A bunch of TCP packets go into a bar, until it’s overcrowded. The next day, half as many go in.
• A bunch of TCP packets walk into a bar. The bartender says, “Hang on just a second, I need to close the window.”
• I’m going to keep telling you this TCP joke until you get it.
• Want to hear a SYN FLOOD joke? -Want to hear a SYN FLOOD joke? -Want to hear a SYN FLOOD joke? -Want to hear a SYN FLOOD joke? -Want to hear a SYN FLOOD joke?
• When I try to send SYNs to chicks, I don’t get any ACKs. Just FINs and RSTs.

Voice

• I always get jittery when making jokes in real time.
• An RTP packet walks into a bar through the wrong entrance. The barman says “You’re not getting any special treatment”.
• The best thing about Delay-Tolerant Networking jokes is that everyone gets them eventually.

More Voice jokes are in this post.

Wireless

• The bad thing about RTS jokes is, you must first get ready to get them told.
• The bad thing about WEP jokes is that they all stink, so better don’t sniff them.
• A joke about IEEE 802.15.5 is pointless if you tell it right.
• Telling a lot of bluetooth jokes will reduce the bandwidth of your WiFi jokes.
• I would tell you a WEP joke, but I need to collect 50,000 packets first.
• I was telling joke to my house neighbor over WiFi, but someone interfered.

SNMP

• The problem with SMTP jokes are, you need some good reason to came back after greylisting and tell them again.
• SNMP walks into a bar and gets unknown object identifier.
• You need to tell a authorized POP3 joke before you can have a SMTP laugh.
• Unfortunately you need MIB files to understand the best SNMP jokes.

HTTP

• The best thing about 404 jokes is… wait, damnit, it’s around here somewhere…
• There’s no more 301 jokes because they have all been moved permanently.
• HTTP 200 jokes are only OK.

Other

• I tweeted several IPX/SPX jokes, but they can’t reach the Internet.
• A token walks into a bar. Another token can’t walk into the bar because it’s afraid of the dog.
• XML jokes are well-formed
• Open Traffic shaping: All packets are equal, but some are more equal than others.
• CRC jokes tend to get repeated until you get them right.
• Serial jokes must be told bit by bit.
• An NTP packet calls ahead to make sure the bar’s open. By the time he gets there, it’s closed.
• An ICMP Redirect walks into a bar. Everybody moves next door.
• I made an NTP joke once. The timing was perfect.
• See most people talk about the OSI model as having 7 layers but they don’t mention layer 8 where a lot of the problems actually occur.
• When I go to the doctor for a cold and congestion, I usually tell him I have a ton of BECN bits set on the flow of my breathing through my nose.

Fonte: http://rekrowten.wordpress.com/list-of-network-jokes/

Abraços.

Diogo.

Leia também:

• II NetworKaridade
• Os 10 maiores rivais da Cisco
• Ferramentas de rede
• 2 anos de blog
• NetworCare

Uma boa notícia para aqueles que buscam experiência com o software IOS-XR (que roda em equipamentos voltados ao mercado Service Provider, como CRS e ASR9K).

A Cisco está desenvolvendo uma plataforma que roda várias instancias do software em servidores (geralmente virtuais), algo muito parecido com o IOU para emular IOS. Esta plataforma (chamada de XR4U) já está disponível internamente na Cisco e também para parceiros através do PEC (Partner Education Connection). Os “roteadores virtuais” rodam atualmente a versão 4.2.1 do IOS-XR sobre uma plataforma CentOS release 5.8.

Acessei, fiz alguns testes básicos e gostei muito! Uma ótima oportunidade para os profissionais interessados em praticar seus conhecimentos sem necessidade de ter acesso a esse tipo de equipamento.

Abraços.

Diogo.

Leia também:

• XR4U disponível no PEC
• Novo CCNP® Service Provider Certification
• Cisco Live! 365
• Cisco pretende lançar oficialmente o software IOU
• Novo CCNA® Service Provider Certification